Axle wheel end axial thrust assembly

ABSTRACT

An axle assembly for a vehicle including a differential assembly, a first axle tube extending outwardly from a first side of the differential assembly and defining an axle bore, a first axle shaft rotatably received in the first axle tube, and defining an annular groove extending radially inwardly from its outer surface, a retainer nut axially fixed to a distal end of the first axle tube, the retainer nut having an annular flange extending inwardly into the axle bore and defining an annular outer raceway, a snap ring received in the annular groove, and an axial thrust component disposed in the axle bore of the first axle tube between the snap ring and the outer raceway of the retainer nut.

CLAIM OF PRIORITY

This application is a continuation of U.S. patent application Ser. No.15/519,386 filed Apr. 14, 2017, now U.S. Pat. No. 10,183,529, which is a35 U.S.C. § 371 national stage application of PCT/US2015/056954, filedOct. 22, 2015, which claims the benefit of U.S. Provisional PatentApplication No. 62/079,037 filed Nov. 13, 2014, and U.S. ProvisionalPatent Application No. 62/067,165 filed Oct. 22, 2014, the entiredisclosures of which are incorporated herein.

FIELD OF THE INVENTION

The present disclosure relates generally to solid axle assemblies forvehicles and, more specifically, to bearing assemblies that are utilizedon the wheel end sections of such solid axle assemblies.

BACKGROUND

Salisbury solid axles are often used in passenger trucks and sportutility vehicles. Salisbury axles are unique in the fact that the axletransmits driving torque to the wheel as well as carries and transmitsboth radial and axial thrust loads.

As shown in FIG. 1, many existing wheel end bearings 10 for use withsolid vehicle axles include an outer cup 11 that is press-fit into thecorresponding axle tube 12 to maintain location and define an outerraceway for the corresponding rollers 13. No additional retentionfeatures are required for this type of wheel end bearing 10 in that thebearing only handles radial loads. Lubrication for wheel end bearing 10is provided by the same oil sump that provides lubrication to thedifferential gears 15 (FIG. 2) that are disposed at the center sectionof the axle assembly. To maintain lubrication, an oil seal 14 ispress-fitted outboard of the wheel end bearing in axle tube 12.

Radial wheel end loads are handled primarily at wheel end bearing 10,whereas axial loads are not. Rather, as best seen in FIGS. 2 through 4,axial loads are transmitted along axle shaft 16. Typically, “C Locks” 18are utilized to resist outward axial loading and a cross shaft 20disposed between the opposing axle shafts in a housing 25 ofdifferential 17 absorbs inward axial loading. A typical C Lock includesa heavy annular lock ring 19 received in an annular groove 21 formed onthe inboard end of a corresponding axle shaft 16. In the fully assembledconfiguration (FIG. 3), annular lock ring 19 is further received in anannular recess 23 formed in an end face of a corresponding differentialgear 15. During normal operations, inward axial loading has a highermagnitude than outward axial loading due to vehicle dynamics duringcornering. When outward axial load on axle shaft 16 occurs, axle shaft16 attempts to move outwardly from axle tube 12, which causes annularlock ring 19 of the corresponding C Lock 18 to push on the correspondingdifferential side gear 15. Ultimately, the outward axial load isdispersed through differential carrier bearings 24 to housing 25 of thedifferential, as shown in FIG. 4.

When inward axial loading is generated from vehicle cornering, an endface 27 of axle shaft 16 thrusts against differential cross shaft 20, asbest seen in FIG. 2. In turn, the inward axial loading is transmittedthrough differential carrier bearings 24, as shown in FIG. 4.

The present invention recognizes and addresses considerations of priorart constructions and methods.

SUMMARY

One embodiment of an axle assembly for a vehicle includes a differentialassembly, a first axle tube extending outwardly from a first side of thedifferential assembly, the first axle tube including a proximal endadjacent the differential assembly, an opposite distal end, and an axlebore extending therebetween, a first axle shaft rotatably received inthe first axle tube, the first axle shaft including a proximal enddisposed in the differential assembly, an opposite distal end extendingoutwardly from the distal end of the first axle shaft, and an annulargroove extending radially inwardly from its outer surface, a retainernut axially fixed to the distal end of the first axle tube, the retainernut having an annular flange extending inwardly into the axle bore anddefining an annular outer raceway, a snap ring received in the annulargroove of the first axle shaft, and an axial thrust component disposedin the axle bore of the first axle tube between the snap ring and theouter raceway of the retainer nut.

Another embodiment of an axle assembly for a vehicle includes adifferential assembly, a first axle tube extending outwardly from afirst side of the differential assembly, the first axle tube including aproximal end adjacent the differential assembly, an opposite distal end,and an axle bore extending therebetween, a first axle shaft rotatablyreceived in the first axle tube, the first axle shaft including aproximal end disposed in the differential assembly, an opposite distalend extending outwardly from the distal end of the first axle shaft, andan annular groove extending radially inwardly from its outer surface, aretainer nut axially fixed to the distal end of the first axle tube, theretainer nut having an annular flange extending inwardly into the axlebore, a thrust cup axially fixed to an inner bore of the retainer nut,the thrust cup defining an annular outer raceway, a snap ring receivedin the annular groove of the first axle shaft, an annular inner racewaydisposed in the axle bore of the first axle tube adjacent the snap ring,and an axial thrust component disposed in the axle bore of the firstaxle tube between the inner raceway and the outer raceway.

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate one or more embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendeddrawings, in which:

FIG. 1 is a partial cross-sectional view of a wheel end section of aprior art solid axle assembly;

FIG. 2 is a partial perspective view of the prior art axle shaft shownin FIG. 1 and a corresponding differential;

FIG. 3 is a partial perspective view of the prior art axle shaft anddifferential shown in FIG. 2, including a cross shaft of thedifferential;

FIG. 4 is a cut away side view of the prior art axle shaft anddifferential shown in FIG. 2;

FIG. 5A is a perspective view of an axial thrust assembly in accordancewith a first embodiment of the present invention, for use with a solidaxle assembly;

FIG. 5B is a partial cross-sectional view of a wheel end section of asolid axle assembly including the axial thrust assembly shown in FIG.5A;

FIG. 5C is a perspective view of a retainer nut of the axial thrustassembly shown in FIGS. 5A and 5B;

FIG. 5D is a perspective view of a ring lock of the axial thrustassembly shown in FIGS. 5A and 5B;

FIG. 6A is a perspective view of an axial thrust assembly in accordancewith a second embodiment of the present invention, used with a solidaxle assembly;

FIG. 6B is a partial cross-sectional view of a wheel end section of asolid axle assembly including the axial thrust assembly shown in FIG.6A;

FIG. 6C is a perspective view of a flange plate of the axial thrustassembly shown in FIGS. 6A and 6B;

FIG. 7A is a partial cross-sectional view of a wheel end section of asolid axle assembly including a third embodiment of an axial thrustassembly in accordance with the present invention;

FIG. 7B is a perspective view of a ring insert of the axial thrustassembly shown in FIG. 7A;

FIG. 8A is a perspective view of an axial thrust assembly in accordancewith a fourth embodiment of the present invention, for use with a solidaxle assembly;

FIG. 8B is a partial cross-sectional view of a wheel end section of asolid axle assembly including the axial thrust assembly shown in FIG.8A;

FIG. 8C is a partial cross-sectional view of a wheel end section of asolid axle assembly including the axial thrust assembly shown in FIG.8A;

FIG. 8D is a perspective view of a unitized thrust assembly of the axialthrust assembly shown in FIGS. 8A through 8C;

FIG. 9A is a partial cross-sectional view of a wheel end section of asolid axle assembly including a fifth embodiment of an axial thrustassembly in accordance with the present invention;

FIG. 9B is a partial cross-sectional view of a wheel end section of asolid axle assembly including a fifth embodiment of an axial thrustassembly in accordance with the present invention;

FIG. 9C is a perspective view of a ring lock of the axial thrustassembly shown in FIGS. 9A and 9B; and

FIG. 9D is a perspective view of a unitized thrust assembly of the axialthrust assembly shown in FIGS. 9A and 9B.

Repeat use of reference characters in the present specification anddrawings is intended to represent same or analogous features or elementsof the invention according to the disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to presently preferred embodimentsof the invention, one or more examples of which are illustrated in theaccompanying drawings. Each example is provided by way of explanation,not limitation, of the invention. In fact, it will be apparent to thoseskilled in the art that modifications and variations can be made in thepresent invention without departing from the scope and spirit thereof.For instance, features illustrated or described as part of oneembodiment may be used on another embodiment to yield a still furtherembodiment. Thus, it is intended that the present invention covers suchmodifications and variations as come within the scope of the appendedclaims and their equivalents.

Referring now to FIGS. 5A through 5D, a wheel end axial thrust assembly100 for use with a solid vehicle axle in accordance with an embodimentof the present disclosure includes a radial bearing assembly 140, a snapring 136, a thrust bearing assembly 130, and a retainer nut 110 disposedon the wheel end of an axle shaft 106 and corresponding axle tube 102,as discussed in greater detail below. Axial thrust assembly 100 handlesaxial thrust forces that act on axle shaft 106 in the outward direction,thereby obviating the need to utilize C-locks 18 (FIGS. 2 and 3) thatare typically found on existing solid axle assemblies.

As noted above, radial bearing assembly 140 includes an outer cup 142that defines a cylindrical outer race 144 for needle rollers 146. Afirst annular flange 141 and second annular flange 143 extendradially-inwardly from opposite ends of outer race 144. Outer cup 142 ispreferably a machined and ground component made from a carburized gradeof steel to enhance control of the press-fit, bearing clearances, andincrease allowable hoop stresses. As best seen in FIG. 5B, outer cup 142is received in a bore 101 of axle tube 102. Although radial bearingassembly 140 does not handle either inward or outward axial thrustforces that act on axle shaft 102, outer cup 142 is preferably press-fitinto bore 101 to maintain the desired position within axle tube 102. Aswell, outer cup 142 is positioned within bore 101 of axle tube 102 sothat an inner race for the plurality of rollers 146 is formed by anarrowed portion of axle shaft 106, as discussed in greater detailbelow.

Each needle roller 146 includes a cylindrical rolling surface extendingbetween a first end face 145 and a second end face 147. Each first andsecond end face 145 and 147 is transverse to a longitudinal center axisof the corresponding needle roller 146. As such, when needle rollers 146are disposed between outer cup 142 and the outer surface of axle shaft106, first end faces 145 and second end faces 147 are parallel to firstannular flange 141 and second annular flange 143 of outer cup 142.

Snap ring 136 is annular in shape and is received in an annular groove105 on axle shaft 106. Annular groove 105, and therefore snap ring 136,is disposed outboard of radial bearing assembly 140 on an enlarged endportion 107 of axle shaft 106. The diameter of enlarged end portion 107of axle shaft 106 is greater than the diameter of the inboard portion109 that forms the remainder of axle shaft 106. The increased diameterhelps to minimize any additional stresses due to the formation ofannular groove 105 to receive snap ring 136 and its resistance tooutwardly directly axial thrust forces that act on axle shaft 106. Asplit (not shown) in snap ring 136 allows it to be slid over thetransition between the inboard and outboard portions of axle shaft 106.

A thrust washer 134 is preferably disposed outboard of, and adjacent to,an end face of snap ring 136 and forms an inner thrust race for axialbearing assembly 130. An outermost edge and innermost edge of thrustwasher are smaller than the inside diameter of axle tube 102 and largerthan the outside diameter of the axle shaft's enlarged end portion 107,respectively, so that thrust washer 134 is free to rotate about axleshaft 106. As noted, thrust washer 134 serves as an inner thrust racefor thrust bearing 130 and, therefore, its plurality of needle rollers132. An outer thrust race 112 of thrust bearing 130 is formed by aportion of retainer nut 110, as discussed in greater detail below.

Retainer nut 110 is threadedly received on the wheel end of axle tube102. Specifically, a portion 116 of the outer surface of retainer nut'sbody 111 is correspondingly threaded to a portion 131 of the axle tube'sbore 101. Preferably the tolerances between the male threads 116 ofretainer nut 110 and female threads 131 of axle tube 102, when engaged,are such that “backlash” is prevented. Specifically, the idealtolerances between the threads allows for ease of threadedly connectingthe components, but minimizes the possibility of impact or frettingwear. As well, in some embodiments an interference fit between thethreads may be used in which the female threaded component, the axletube, deforms slightly when accepting the male threaded component, theretainer nut.

Once retainer nut 110 and axle tube 102 are threadedly engaged, a ringlock 138 is used to non-rotatably secure retainer nut 110 in the desiredposition. Specifically, a tab 139 of ring lock 138 engages one of aplurality of lock notches 137 formed on retainer nut 110. Cylindricalbody 111 of retainer nut 110 includes an open end defining a bore 113, afirst radial flange 115 depending outwardly from the open end ofcylindrical body 111, a second radial flange 117 depending inwardly fromthe end of cylindrical body 111, opposite its open end, and an axialflange 119 depending inwardly from the inner perimeter of second radialflange 117. As best seen in FIG. 5, axial flange 119 is concentric withcylindrical body 111, thereby defining an abutment surface for theinnermost end faces of the plurality of needle rollers 132 of thrustbearing 130. An innermost end face of the retainer nut's second radialflange 117 serves as outer thrust race 112 for the thrust bearing'splurality of needle rollers 132. Additionally, first radial flange 115defines a plurality of lock notches 137 on its outer perimeter.

As shown in FIG. 5B, an annular groove 180 is defined in the outersurface of the retainer nut's cylindrical body 111, adjacent firstradial flange 115. An O-ring 190 is received in annular groove 180 andforms a seal with the inner surface of axle tube 102 to help retainlubricating fluids therein. Additionally, an oil seal 150 including anannular body portion 151 and annular sealing member 152 is received inbore 113 defined by cylindrical body of retainer nut 110 to help retainlubricating fluids in axle tube 102. Specifically, annular body 151 ispress-fit in bone 113 so that sealing member 152 contacts the outersurface of axle shaft 106.

During assembly, retainer nut 110 is rotated so that it moves inwardlyinto axle tube 102 until the inner end of the axle shaft bumpsdifferential cross shaft 20, as noted above. Next, retainer nut 110 isunthreaded from axle tube 102 to provide the desired amount of clearancebetween the end of the axle shaft and the differential cross shaft 20when axle shaft 106 is in its outermost position. In the present case,retainer nut 110 is rotated so that tab 139 of ring lock 138 is able toengage the subsequent lock notch 114 on the first radial flange 115 ofretainer nut 110, next to the notch that is engageable when axle shaft106 abuts the differential cross shaft 20. Ring lock 138 is then securedin position with a mounting bolt 103 to lock retainer nut 110 and,therefore, the axial thrust assembly components in place.

As best seen in FIG. 5B, during vehicle operations, axial thrust forcesacting on axle shaft 106 in the outward direction are transferred toretainer nut 110 by way of snap ring 136. Specifically, snap ring 136moves outwardly with axle shaft 106 as it is received in annular groove105 thereof. The outboard end face of snap ring 136 abuts thrust washer134, which acts as inner thrust race of thrust bearing 130. As such,thrust washer 134 transfers the thrust force to outer thrust race 112,and therefore retainer nut 110, by way of the thrust bearing needlerollers 132. In turn, retainer nut 110 transfers the outwardly directedaxial thrust force to axle tube 130 by way of the threaded connectiontherebetween. As previously discussed, inwardly directed axial thrustforces acting on axle shaft 150 are transferred from the innermost endof axle shaft 120 to cross shaft 20 (FIGS. 3 and 4) of the axle'sdifferential.

In an alternate embodiment of a wheel end axial thrust assembly 200 inaccordance with the present disclosure, shown in FIGS. 6A through 6C, athreaded flange plate 160 is utilized to secure retainer nut 110 in thedesired position with respect to axle tube 102. Flange plate 160includes a base plate 164 defining a plurality of fastener apertures166, and an axially-extending cylindrical body 168 that defines acentral bore 167 in base plate 164. As shown, body 168 includes aportion 169 of its inner surface that is correspondingly threaded tothreaded portion 116 of retainer nut 110. Flange plate 160 is mounted tobrake assembly 201 by using brake assembly mounting bolts 103 that passthrough fastener apertures 166. As best seen in FIG. 6B flange plate 160acts as an axle tube extension and hardened threads 169 receive threadedportion 116 of retainer nut 110. The remaining components of thisembodiment function similarly to the previously discussed embodiment,shown in FIGS. 5A and 513, which includes an axle tube with a threadedinner diameter, This alternate embodimentallows for the threaded flangeplate 160 to be removed and replaced if the threads become damaged, yetpreferably allows axle shaft 106 to be removed without removal ofthreaded flange 160.

In yet another embodiment of an axial thrust assembly 300 in accordancewith the present disclosure, a threaded ring insert 170 is used tosecure threaded retainer nut 110 to axle tube 102. As best seen in FIG.7B, ring insert 170 includes an annular body 171 and a plurality offlexible tabs 175 extending rearwardly therefrom. Each tab 175 includesa threaded inner surface 172 and a lip 176 extending radially-outwardlyfrom its distal end. The plurality of lips 176 define an annular boss174. As well, each tab 175 has an increasing taper from its proximal endadjacent annular body 171 to its distal end.

As shown in FIG. 7A, the tapered and expandable threaded ring insert 170is press-fit into the end of axle tube 102 so that the lip of each tab175 is adjacent annular groove 104 of axle tube 102. As previouslynoted, the threaded inside diameter of ring insert 170 is tapered sothat when the threaded portion 116 of retainer nut 110 is screwed intothe ring insert, each tab 175 expands outwardly. As such, each lip 176of each tab 175 extends outwardly into annular groove 104 formed on theinner surface of axle tube 102. As annular boss 174 expands into groove104 of the axle tube, the retainer nut 110 and insert 170 become axiallyfixed within the axle tube.

Threaded retainer nut 110 may be screwed into threaded insert 170 untilthe innermost end of axle shaft 106 comes in contact with differentialcross shaft 20 (FIG. 3) and, similar to the previously discussedembodiments, may be unscrewed one lock notch 137 of retainer nut 110 andlocked in place with ring lock 138. The expanding threaded insert 170allows for a constant spring pressure on the retainer nut to maintainposition and eliminate any backlash and potential fretting fromvibrations while driving the vehicle.

Referring to FIGS. 8A through 8D, another embodiment of a wheel endaxial thrust assembly 400 in accordance with the present disclosureincludes a radial bearing assembly 140, a snap ring 136, a thrustbearing assembly 130, a retainer nut 410, an inner thrust race 134 and athrust cup 430 which includes a radially-inwardly depending flange 432that defines an outer thrust race. As well, thrust cup 430 defines aradially-outwardly depending lip 434 that is received in an annulargroove 408 that s defined by the inner surface of retainer nut 410.Retainer nut 410 also defines a radially-inwardly depending lip 412which has an inner perimeter having a smaller diameter than the outerdiameter of inner thrust race 134. As such, inner thrust race 134 andthrust bearing assembly 130 are received between lip 412 and outerthrustrace 432 of thrust cup 430 as a unitized thrust assembly, as shown inFIG. 8D, when lip 434 of thrust cup 430 is received in annular groove408.

This configuration facilitates assembly as retainer 410, inner thrustrace 134, thrust bearing assembly 130 and thrust cup 430 may be shippedand installed as a unitized assembly. An O-ring 440 is received in anannular groove 442 that is defined by an inner surface of axle tube 102so that O-ring 440 forms a seal about the outer surface of retainer nut410. Preferably, an oil seal 450 including an annular body portion 451and an annular sealing portion 452 is retained within thrust cup 430 byan annular ring 452 that depends radially outwardly from the bodyportion and engages an annular groove formed by hrust cup 430. Oil seal450 forms a seal with he outer surface of the axle shaft. As well, outercup 142 of radial bearing 140 is preferably press-fit inside axle tube102 axially inwardly of thrust bearing assembly 400, and the axle shaftis able to slide axially with respect to radial bearing 140.

During assembly, retainer nut 410 of the unitized bearing assembly isthreaded into the distal end of axle tube 102, thereby causing thrustcup 430 to push thrust bearing 130 up against inner thrust race 134which is, in turn, is pushed up against snap ring 134. As with theprevious designs, thrust hearing 130 includes a plurality of needlerollers 132. As snap ring 136 is received in an annular groove 105formed in the axle shaft, snap ring 136 is pushed axially inwardly sothat the end of the inner axle shaft abuts against the differentialcross shaft 20 (FIG. 3). Next, retainer nut 410 is unthreaded from theaxle tube to provide the desired amount of clearance between the end ofthe axle shaft and the differential cross shaft when the axle shaft isin its outermost position. In the present case, retainer nut 410 isrotated so that ring lock 138 is able to engage the subsequent locknotch 414 with lock tab 139, which is typically the one that is next tothe notch that is engageable when the axle shaft abuts cross shaft 20.Ring lock 138 is then bolted in position to lock retainer nut 410 and,therefore, the unitized bearing assembly components in place.

As best seen in FIG. 8C, during vehicle operations, axial thrust forcesacting on axle shaft 106 in the outward direction are transferred toretainer nut 110 by way of snap ring 136. Specifically, snap ring 136moves outwardly with axle shaft 106 as it is received in annular groove105 thereof. The outboard end face of snap ring 136 abuts thrust washer134, which acts as inner thrust race of thrust bearing 130. As such,thrust washer 134 transfers the thrust force to outer thrust race 432,and therefore thrust cup 430, by way of the thrust bearing needlerollers 132. Next, thrust cup 430 transfers the axial thrust force toretainer nut 110 by way of its lip 434 being received in the retainernut's annular groove 408. In turn, retainer nut 110 transfers theoutwardly directed axial thrust force to axle tube 130 by way of thethreaded connection therebetween. As previously discussed, inwardlydirected axial thrust forces acting on axle shaft 106 are transferredfrom the innermost end of axle shaft 120 to cross shaft 20 (FIGS. 3 and4) of the axle's differential.

Referring to FIGS. 9A through 9D, another embodiment of a wheel endaxial thrust assembly 500 in accordance with the present disclosureincludes a radial bearing assembly 140, a snap ring 136, a thrustbearing assembly 130, a retainer nut 410, an inner thrust race 134 and athrust cup 430 which includes a radially-inwardly depending flange 432.Thrust cup 430 defines a radially-outwardly depending lip 434 that isreceived in an annular groove 408 that is defined by the inner surfaceof retainer nut 410. Retainer nut 410 also defines a radially-inwardlydepending lip 412 which has an inner perimeter having a smaller diameterthan the outer di iter of inner thrust race 134. As such, inner thrustrace 134 and thrust bearing assembly 130 are received between lip 412and outer thrust race 432 of thrust cup 430 as a unitized thrustassembly, as shown in FIG. 9D, when lip 434 of thrust cup 430 isreceived in annular groove 408.

Axial thrust assembly 500 differs only from the fourth embodimentdescribed in regard to FIGS. 8A through 8D in that thrust bearingassembly 130 includes caged needle rollers 146 and dedicated inner andouter raceways 402 and 404, a cartridge-type oil seal 450, and adifferent ring lock 438. As such, only those components are described atthis point. As best seen in FIG. 9B, needle rollers 132 of thrustbearing assembly 130 are contained by first and second cage halves 401and 403, which are in turn contained within inner and outer raceways 402and 404. As such, thrust bearing assembly 130 may be assembled as aunitized bearing prior to being installed into axial thrust assembly500, thereby facilitating assembly. As best seen in FIG. 9B, oil seal450 includes a first body portion 452 and a second body portion 454 towhich an annular seal 456 is affixed. Second body portion 454 is securedto first body portion 452 so that annular seal 456 is disposed withinfirst body portion 452. As such, annular seal 456 is protected fromabrasions, tears, etc., when installing oil seal 450 on axle shaft 406.Oil seal 450 is slidably received in the bore defined by thrust cup 430in a press-fit.

Referring now to FIG. 9C, ring lock 438 of the present embodimentincludes a pair of axially extending tabs 439 defining a notch 139atherebetween. Notch 139a is configured to slideably receive one of aplurality of protrusions 137a that depend radially outwardly fromretainer nut 410. After the desired protrusion 137a is determined, asdiscussed with regard to the previous embodiments, ring lock 438 issecured to brake assembly 201 by a mounting bolt 103.

While one or more preferred embodiments of the invention are describedabove, it should be appreciated by those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the scope and spirit thereof. It is intended thatthe present invention cover such modifications and variations as comewithin the scope and spirit of the appended claims and theirequivalents.

What is claimed:
 1. An axle assembly for use with a differentialassembly of a vehicle, comprising: a first axle tube extending outwardlyfrom a first side of the differential assembly, the first axle tubeincluding a proximal end adjacent the differential assembly, an oppositedistal end, and an axle bore extending therebetween; a first axle shaftrotatably received in the first axle tube, the first axle shaftincluding a proximal end disposed in the differential assembly, anopposite distal end extending outwardly from the distal end of the firstaxle shaft, and an annular groove extending radially inwardly from itsouter surface; a retainer nut axially fixed to the distal end of thefirst axle tube, the retainer nut having an annular flange extendinginwardly into the axle bore and defining an annular outer raceway; asnap ring received in the annular groove of the first axle shaft; and anaxial thrust component disposed in the axle bore of the first axle tubebetween the snap ring and the outer raceway of the retainer nut.
 2. Theaxle assembly of claim 1, further comprising an annular inner racewaydisposed in the axle bore of the first axle tube between the snap ringand the thrust component.
 3. The axle assembly of claim 1, wherein thethrust component comprises a plurality of needle rollers.
 4. The axleassembly of claim 1, further comprising a radial bearing assemblyincluding an outer race and a plurality of roller elements rotatablyreceived therein, the radial bearing assembly being axially fixed withinthe axle bore of the first axle tube.
 5. The axle assembly of claim 4,wherein the thrust component further comprises a cage defining aplurality of roller pockets, each needle roller being rotatably disposedin a corresponding roller pocket.
 6. The axle assembly of claim 1,wherein the retainer nut is in threaded engagement with a threadedportion of the axle bore.
 7. The axle assembly of claim 1, wherein aflange plate is non-rotatably fixed with respect to the distal end ofthe axle tube and the retainer nut is in threaded engagement with thethreaded portion of the flange plate.
 8. The axle assembly of claim 1,wherein a ring insert is disposed adjacent the distal end of the axlebore and is axially fixed with respect to the axle tube, and theretainer nut is in threaded engagement with an inner surface of the ringinsert.